Posted
by
Zonk
on Friday November 16, 2007 @07:32PM
from the edison-we-barely-knew-ye dept.

cell-block-9 writes "Today the last section of the old Edison DC power grid will be shut down in Manhattan. 'The last snip of Con Ed's direct current system will take place at 10 East 40th Street, near the Mid-Manhattan Library. That building, like the thousands of other direct current users that have been transitioned over the last several years, now has a converter installed on the premises that can take alternating electricity from the Con Ed power grid and adapt it on premises.' I guess Tesla finally won the argument."

Just like most of us here on Slashdot don't know (without the assistance of a search engine) who won the 1982 Super Bowl. Different things matter to different people and most people have things to worry about rather than wondering who the proponents of power transport via AC were.

Most of us here on/. certainly know who Mr. Tesla is and what he pushed for and we should take pleasure in being in such distinct company...except for the trolls and turds.

but the real overriding realization with democracy and capitalism is that however much you think they suck, and they do suck in many ways, they are still better than any other system we can think of and have tried

Or that he died broke and alone because people like Edison stole his ideas... Tesla's failure is a perfect example of capitalism at work.

Much of the good ideas that really propel technology are that way. Capitalism rewards manipulative wheeler-dealers far more than creativity. It rewards those who can best exploit creative ideas, not make them.

No. Capitalism is the best system available, but that doesn't make it fair. It is up to the people within the system to try to make it fair. That includes pointing out the problems with it. His criticism isn't meaningless, it's important.

He was too busy DISCOVERING how these things worked to be able to "read" them all laid out nicely in some book. Yes, some of his inventions were a bit crazy, but we owe a lot of progress to the man. If it weren't for him, we'd be stuck with Edison's crappy DC systems and the modern electrical systems we have today would not exist. Edison helped ruin the poor man just to sell his crap and he did it via evil fearmongering, doing things like electrocuting an elephant with AC.

Also, the wireless power transfer IS possible. Too dangerous to actually use, but possible. And he left behind plenty of shocked people to prove it (literally...).

whether or not Churchill said it, "Democracy is the worst form of government imaginable. Except all the others."

One could easily apply this to economic systems as well. The only thing I could think of that would be better would be some Deus Ex-type computer-AI directing or at least regulating human activities. Self regulation seems to be one of our biggest difficulties.

What you're hearing is not a dynamotor, but something called a Ward Leonard drive. It's a fixed-speed motor driving a generator, but its purpose is speed control. The field current of the generator, which is small, is adjusted to control the larger output of the generator. The variable output of the generator then drives the elevator motor. The Ward Leonard drive is thus a big power amplifier. Until power semiconductors got big enough, which wasn't really until the 1980s, this was the most effective way to smoothly speed-control large motors.

A dynamotor has a common field for the input and output sides, but a Ward Leonard drive does not.

but I didn't realise that anything was still being served anything other then AC out of the wall. I guess in the New york area was some of the original electrical installations. It is a shame that Tesla's lab was destroyed because I would bet that he could have come up with some more stuff that even today would make peoples jaws drop.

actually no, that means 80+ years ago that was true but now a high voltage dc transmission system is in fact more efficient, uses less condutors, eliminates need for sychnonization between different systems. HVDC also preferred for undersea long distance transmission because of less capacitive losses.

DC is still far more of a pain to convert than AC at least if you want high efficiancy and high reliability. While HVDC is certainly more efficiant for very long or undersea transmission lines it would be extremely difficult to build a power distribution grid based on it.

I would assume it wasn't better because in most cases electricity has to travel over a long distance UNUSED between production and final usage point (ie: power generator and someone's home). AC can relatively easily be upped to high voltage which is good for sending over long distance (much higher efficiency) IF you don't need to use it along the way. Also I think single speed AC motors are easy to make.

Subways (and the like) are unique because the transmission line is also your final output/usage point. You CAN'T send electricity at high voltage for part of the trip. So you only need to make electricity at one voltage and feed it straight into the line with no conversions for efficiency. It doesn't matter that you can't change the DC voltage as it would actually be counter productive to do so.

This is also why I assume subways have their own dedicated power stations or used to at least.

As for capitalism being fair (or not), my grandma always said, "If you dont work you dont eat."

That's a good argument against capitalism, where capital, if you have it, works for you. Start out with enough, and you can eat damn well on investments and compound interest without ever working.And on the opposite side of the scale, if you can't work, you don't eat either.

Personally, I think effort-driven communism ("How much you eat depends on your effort to contribute") is theoretically the best system, but chances are it will never be tried. Too many people have an interest in making their own slice of cake bigger, their efforts less, and too much cultural, genetic and religious emotional baggage to ever allow one's own kids to start at zero. (Abolishing inheritance is one of the first necessary steps in ensuring equality.)

No, your regular computer power supply does not provide hundred of amps - tens, tops, and that is for a really power hungry system on a 110VAC line. Switching power supplies prices scale up rapidly with increasing power output.I didn't say anything about the "power supply", I was talking about the Motherboard, which feeds electricity to that power hungry CPU, taking in the 5VDC at 20 Amps and convert it to 1.33 VDC at 60 amps per unit

The latest CPU voltage-regulator specifications from Intel and AMD call for load-current slew rates of 50 to 200A/sec and peak currents of 60 to more than 120A. These demands are transforming the design of portable power supplies to levels almost like those of utility power. Designing high-current, VRM-compliant CPU power supplies [edn.com]

Now we have multi-CPU and multi-core CPU; that easily hundreds of amps on a MOBO; it mind boggling but your computer might be consuming as many amps at 1.33 volts as you4 entire house at 225/117VAC.